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            <h2 class="title" style="clear: both"><a id="envadd_data_dir"></a>DbEnv::add_data_dir()</h2>
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      <pre class="programlisting">#include &lt;db_cxx.h&gt;

int
DbEnv::add_data_dir(const char *dir); </pre>
      <p>
         Add the path of a directory to be used as the location of the access
         method database files.  Paths specified to the 
         <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a>  function will be
         searched relative to this path.  Paths set using this method are
         additive, and specifying more than one will result in each specified
         directory being searched for database files.  
    </p>
      <p>
         If no database directories are specified, database files must be named
         either by absolute paths or relative to the environment home
         directory. See 
         <a href="../../programmer_reference/env_naming.html" class="olink">Berkeley DB File Naming</a> 
         for more information.
    </p>
      <p>
         The database environment's data directories may also be configured
         using the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file.  The syntax of the entry
         in that file is a single line with the string "add_data_dir", one
         or more whitespace characters, and the directory name.
         Note that if you use this method for your application, and you also want to use the
         <a class="xref" href="db_recover.html" title="db_recover">db_recover</a> or
         <a class="xref" href="db_archive.html" title="db_archive">db_archive</a>
         utilities, then you should create a <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file and set
         the "add_data_dir" parameter in it.
    </p>
      <p>
         The <code class="methodname">DbEnv::add_data_dir()</code> method configures operations performed
         using the specified <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  
         handle, not all operations performed on the underlying database environment.
    </p>
      <p>
         The <code class="methodname">DbEnv::add_data_dir()</code> method may not be called after the 
         <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a>  method is called.
         If the database environment already exists when 
         <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a>  is called, the
         information specified to <code class="methodname">DbEnv::add_data_dir()</code> must be consistent
         with the existing environment or corruption can occur.
    </p>
      <p>
         The <code class="methodname">DbEnv::add_data_dir()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
    </p>
      <div class="sect2" lang="en" xml:lang="en">
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              <h3 class="title"><a id="idp6565744"></a>Parameters</h3>
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        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6566392"></a>dir</h4>
              </div>
            </div>
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          <p>
                  The <span class="bold"><strong>dir</strong></span> parameter is a
                  directory to be used as a location for database files.
                  This directory must currently exist at environment open
                  time.
             </p>
          <p>
                 When using a Unicode build on Windows (the default), this
                 argument will be interpreted as a UTF-8 string, which is
                 equivalent to ASCII for Latin characters.
             </p>
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      <div class="sect2" lang="en" xml:lang="en">
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              <h3 class="title"><a id="idp6562440"></a>Errors</h3>
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        <p>
             The <code class="methodname">DbEnv::add_data_dir()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6588112"></a>EINVAL</h4>
              </div>
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          <p>
                If the method was called after <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> 
                was called; or if an invalid flag value or parameter was specified.
            </p>
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      <div class="sect2" lang="en" xml:lang="en">
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            <div>
              <h3 class="title"><a id="idp6589440"></a>Class</h3>
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        <p>
            <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  
        </p>
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      <div class="sect2" lang="en" xml:lang="en">
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              <h3 class="title"><a id="idp6562656"></a>See Also</h3>
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        <p>
             <a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a> 
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